Polyoxalates have been previously prepared by ester interchange with diols such as ethylene glycol, 1,3-propanediol, or 1,4-butanediol with diethyloxalate [Carothers et al., J. Am. Chem. Soc., 52, 3292 (1930); Gordon et al., Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.)31, 507 (1990); Thibeault et al., J. Polym. Sci., Pt. A: Polym. Chem., 28, 1361 (1990); Shalaby et al., U.S. Pat. No. 4,141,087 (1979)], by reactions of oxalic acid with alkylene glycols [Ellis, U.S. Pat. No. 2,111,762 (1938)], and by condensations of diols with oxaloyl chloride [Piraner et al., Makromol. Chem., 193, 681 (1992)]. Linear polyesters have also been prepared by reactions of dicarboxylic acids and diols [Carothers, U.S. Pat. Nos. 2,071,250 and 2,071,251].
Poly(methylene sebacate) was synthesized via a reaction of cesium sebacate with bromochloromethane (Cimecioglu et al., Journal of Polymer Science: Part A: Polymer Chemistry, 30:313-321 (1992); Cimecioglu, A. L. and G. C. East, Makromol. Chem. Rapid Commun., 1989, 10:319), similarly, poly(methylene terephthalate) was synthesized via a reaction of cesium or potassium terephthalate with dibromomethane or bromochloromethane (Cimecioglu et al., Journal of Polymer Science: Part A: Polymer Chemistry 26:2129-2139 (1988)). The highest M.sub.n reported by A. L. Cicecioglu and G. C. East, (J. Polym. Sci., Pt. A: Polym Chem., 1992, 30:313) was 42,300; their polymers were prepared by reaction of cesium terephthalate with bromochloromethane in N-methylpyrrolidone. East and Morshed (Polymer, (1982) vol. 23:168-170 and 1555-1557) have accomplished the synthesis of poly(methylene esters). Poly(methylene terephthalate) is listed as one of the base layers of a film for cassette-type magnetic tape, however, no reference to a preparation was made. (Shiba, H., DE 3,306,089, Sep. 1, 1983; JP Appl. 82/ut24503, Feb. 23, 1982; Chem. Abst., 1983, 99, 213807).
Poly(ethylene terephthalate) (PET) is a commercially important polyester having many applications. PET is known under trade names Dacron.RTM. (DuPont), Mylar.RTM. film, Kodel.RTM. (Eastman Kodak) and Terylene.RTM. (Terene). Of several methods of preparation, the most common is the catalyzed ester interchange between dimethyl terephthalate and ethylene glycol involving removal of methanol to drive the reaction to completion. Poly(ethylene terephthalate) was reportedly prepared by reaction with cesium terephthalate; however, no details are given and the other reactant was not mentioned (G. C. East and M. Morshed, Polymer, 1982, 23:168). A commercial sample of poly(ethylene terephthalate) had M.sub.n =3,600. Poly(ethylene isophthalate) has been previously synthesized by Nishikubo, T. and K. Ozaki (Polym. J. 1990, 22:1043).
Poly(p-xylene terephthalate) was previously prepared by the following method: Reaction of sodium or potassium terephthalates with p-xylylene dichloride or dibromide in the presence of crown ethers (15-crown-S or 18-crown-6). Low yields and low molecular weights were reported. [G. Rokicki, J. Kielkiewicz, and B. Marciniak, Polimery (Warsaw), 1982, 27:374; Chem. Abst., 1982, 99:38837].
Poly(m-xylene terephthalate) was reportedly synthesized by reaction of isophthalic acid, 1,8-diazabicyclo-[5.4.0]-7-undecene, and m-xylylene dibromide in dimethylformamide or dimethylsulfoxide. (T. Nishikubo and K. Ozaki, Polym. J., 1990, 22:1043). The polymer was reported to have moderate viscosity (0.19 dlg.sup.-1).
Bis (tetrabutylammonium) terephthalate was reported as a component in crosslinked vinyl chloride resin foam compositions (Otsuka Chemical Co., Ltd., Jpn. Pat. 582154430, December 1983; Chem. Abst., 1984, 100:175926). IR and Raman spectra have been reported for bis (tetraethylammonium) terephthalate (Makarevich, N. I., and Sushko, N. I., Zh. Prikl. Specktrosk., 1989, 50:65; Chem. Abst., 1989, 110:201792).
Ever since health concerns about asbestos began to surface, producers have been driven to develop suitable alternatives. Traditionally, asbestos has been woven into cloths and garments, compressed into boards, gaskets, and pipe coverings, and used as a filler and reinforcement in paint, asphalt, cement and plastic. To date, no single product has emerged that is as inexpensive, inert, strong or incombustible as asbestos.
The poly(methylene oxalate) (PMO) {systematic name: poly[oxy(1,2-dioxo-1,2-ethanediyl) oxymethylene]}, of the present invention cannot be prepared by any of the methods described above because the glycol that would be needed (HOCH.sub.2 OH) is not stable under normal conditions but decomposes into formaldehyde and water. Poly(methylene oxalate) has unusual properties useful, for example, in the formulation of objects which are non-flammable and resistant to high temperatures and action of organic solvents.
Based on the synthesis of poly(methylene oxalate), a new synthesis of poly(alkylene dicarboxylates) and copolymers of poly(alkylene dicarboxylates) is provided by the present invention. New copolymers are provided, in particular, methylene copolymers, as well as polymers with new end groups. The methods of the present invention allow the synthesis of polymers and copolymers having molecular weights higher than previously described.